What if the tanks had cool down abilities? Their own kind of AOE ability.
Sapien Tanks put up a smoke screen that causes a miss chance/0 damage dealt to anything inside the smoke, i.e. attacking from outside still suffers the miss chance.
Khralean Pinzers spring up roots that lock units in place.
Titan Plasmas send out an acoustic pulse that vibrates metals to liquid, cutting all armor in half.
Maybe the effect spreads out two tiles in each direction, making a flower pattern. Outer smoke fades after one turn. One turn root/stun in outer tiles, two turns for up close. 25% armored reduction in outer tiles. Something like that. Does these abilities affect friendly units? Maybe.